Re: [PATCH v2] fs/dcache.c: avoid soft-lockup in dput()

From: Vaishali Thakkar
Date: Fri Sep 16 2016 - 08:51:27 EST




On Friday 16 September 2016 05:40 PM, Al Viro wrote:
> On Fri, Sep 16, 2016 at 01:19:19PM +0530, Vaishali Thakkar wrote:
>
>> Hi,
>>
>> Just a question regarding this change. As after this change
>> dput() is sleepable, is it still safe to use if under the
>> spinlock in the function d_prune_aliases?
>
> It has always been sleepable and it wouldn't have been safe to use
> under spinlocks. Which d_prune_aliases() does not do - __dentry_kill()
> is called with dentry, its parent and its inode (if present) all locked and
> it drops all those locks before returning.

Ah, I see. Alright. Thanks for the clarification.

>

--
Vaishali